Four member 100x microscope objective

ABSTRACT

A four member achromatic oil immersion microscope objective having a numerical aperture of substantially 1.25 and a magnification of substantially 100X.

United States Patent Shoemaker (451 May 2,1972

FOUR MEMBER 100x MICROSCOPE OBJECTIVE inventor: Arthur H. Shoemaker, Erie, N.Y.

Assignee: American Optical Corporation,

Southbridge, Mass.

Filed: Mar, 18, 1971 Appl. No.2 125,623

US. Cl. ..350/224, 350/l 75 ML, 350/176, 7 350/177 Int. Cl. ..G02b 21/02 Field of Search ..350/224, 176, I77, 175 ML PARALLEL LIGHT Primary Examiner-John K. Corbin Attorney-William C. Nealon, Noble S. Williams, Robert .1. Bird and Bernard L. Sweeney ABSTRACT A four member achromatic oil immersion microscope objective having a numerical aperture of substantially 1.25 and a magnification of substantially 100x.

2 Claims, 1 Drawing Figure Patented May 2, 1972 3,659,924

PARALLEL LIGHT R 2 IN VE N TOR Arthur H Shoemaker by MW Attorney 1 FOUR MEMBER 100x MICROSCOPE OBJECTIVE BACKGROUND OF THE INVENTION This invention relates to improvements in a microscope ob jective, and in particular to an achromatic oil immersion microscope objective with a numerical aperture of substantially 1.25 and a magnification of substantially IOOX. It is the object of the present invention to provide such a microscope objective which is well corrected for the usual chromatic image aberrations as well as spherical aberration, coma, and astigmatism, while having a substantially flat image field when used with a telescope objective as described for example in US. Pat. No. 3,437,398.

DRAWING In the drawing, microscope objective is represented by a plurality of lenses viewed transversely to their axes.

DESCRIPTION Referring now to the drawing, a microscope objective is generally shown at 2. It includes a front doublet 4, a single lens 20 6, a triplet 8, and a doublet 10, all of said lenses in axial align- Doublet 4 includes a plano-convex lens I and a concavoconvex lens Il. Lens 6 is a concave-convex positive meniscus shaped lens also designated as III. Triplet 8 includes a doubleconvex lens IV, a double concave lens V, and a double convex lens VI together forming a positive double convex triplet Doublet 10 includes a convex-plane lens VII and a plane-concave lens VIII, together forming a convex-concave negative doublet.

The lens parameters are as follows: The successive lens radii are designated R1 R12, where a minus sign indicates radii on centers of curvature lying on the object of side of their vertices. The axial thickness of successive lens elements are designated Tl T8. The successive axial spaces from the object plane 12 are designated S1 S4. The refractive indices of the successive lens elements are designated NDI ND8. The Abbe numbers of the successive lens glasses are designated-y 1 y 8.

The above mentioned parameters are related to the focal length according to the following constructional data. The ND and Abbe numbers are pure numbers and the other parameters are in units of millimeters.

ment. Objective 2 is shown disposed relative to an objective plane 12 supporting a specimen l4, (exaggerated scale) with immersion oil in the space between the specimen I4 and the first lens element.

The foregoing parameters of radius, thickness, and space are based on the value ofF. The value of F in this case. as an example, is 1,8277. At this focal length, the absolute values of the foregoing data is as follows:

F=l.8277 MAUNIFICATION=IO0X N.A.=i.25

What is claimed is:

1. An achromatic microscope objective having a magnification of substantially lOOX and a numerical aperture of substantially 1.25 for forming an image of an object plane, said image being well corrected for chromatic aberrations, coma, astigmatism, and curvature of image field, said objective comprising:

a front piano-convex lens member I;

a second concavo-convex lens member ll;

2. An achromatic microscope objective having a magnification of substantially lOOX and a numerical aperture of substantially 1.25 for forming an image of an object plane, said image being well corrected for chromatic aberrations, coma, astigmatism, and curvature of image field, said objective comprising:

a front plane-convex lens member I;

a second concave-convex lens member ll;

said front and second members forming a doublet;

said front and second members forming a doublet; a third concave-convex lens member III; a third concave-convex lens member lll; a fourth d0l1bl COIIWX lens member a fourth double convex lens member W; a fifth double concave lens member V; a fifth double concave lens member V; a sixth double convex lens member VI; a sixth double convex lens member Vl; said fourth, fifth and sixth members forming a triplet; said fourth fifth and sixth members forming a triplet; a seventh convex-plane lens member Vll; a seventh convex-plano lens member Vll; an eighth plane-concave lens member Vlll; an eighth plano-concave lens member Vlll; said seventh and eighth members fonning a doublet; said seventh and eighth members forming a doublet; all of said lens members being axially aligned; all of said lens members being axially aligned; the parameters of lens radii (R1 R12), lens thicknesses the parameters of lens radii (R1 R12), lens thicknesses (T1 T8), axial spaces among lens elements and object (Tl T8), axial spaces among lens elements and object plane (S1 S4), refractive indices (NDl ND9) and plane (S1 S4), refractive indices (NDl ND9) and Abbe numbers (-y1 -y9), being determined by the follow- Abbe numbefs (7 -2 bemgfietemlmed y the follow ing relationship wherein all radii, thicknesses, and spaces ing relationship wherein all radii, thicknesses, and spaces are in millimeters; are in millimeters:

MAGNIF1CA'IION=100X N.A.=1.2li

Refractive Abbe Radius Thickness Space Index Number Lens R '1 S ND v S =.1740F R1= Plano T1=.2730F ND1=L51700 vl=64.5 R1: --.6779F T =.s207F ND2=L88050 2=41.0 R3: -.8596F s =.0109F R4= 6.53Z8F III T;=1.5254F ND3=L88050 v3=4l.0

R5= 2.66fi7F S;=.1641F Rs=7.3623F IV Ti=1.8lF ND4=L78833 v4=50.4

R1= 2.2979F V T5=.6566F ND5=1.80491 v5=25.4

Rs=2.7335F R9= 1l.95G6F v1 Tn=l.794fiF ND6=1A8651 v6=84.4

S4 0.9705F R =3.9U41F V] l. T1= 1.68521 ND7= 1.80784 v7=40.7

ltu=llnno V11 1' Ta=.65(i(il" ND8=L61710 v8=53.9

R12=2A982F F=l.8277 MAGNIFICATION=1OOX NA. 1.25

I Refractive Abbe Radius Thickness Space Index Number Lens R 'I S v S =,31s R| Plano I L.v T,=.600 Nl)l=l.51700 vl=64.54

R2=1.239 Il 'I==1.500 ND2=1J98050 92 41.01

s,= .020 ni= 11.940 HL 'I.1=2.788 Nl)3=l.88050 v3=4l.0l

S: .300 ltr.=- 13.454; W l.=3.320 xn4=1.1sss3 -4=5M1 R7=4.200 V '1 =1.200 Nl)5=l.804!;1 -5=25A2 m= 4.906 V -R=2L853 I Ta=3280 NI)6=1.48651 6=s4.46

S.= 12.740 Rio=7.300 1r '1.-=3.0sn Nn7=1.s07s4 r7=-i0.T-i

R =Plnn0 \lll 'ls=l.'..ll(l Nns=im710 --s=53.m

R|2=-L5liti 

1. An achromatic microscope objective having a magnification of substantially 100X and a numerical aperture of substantially 1.25 for forming an image of an object plane, said image being well corrected for chromatic aberrations, coma, astigmatism, and curvature of image field, said objective comprising: A FRONT PLANO-CONVEX LENS MEMBER I; a second concavo-convex lens member II; said front and second members forming a doublet; A THIRD CONCAVO-CONVEX LENS MEMBER III; a fourth double convex lens member IV; a fifth double concave lens member V; a sixth double convex lens member VI; said fourth , fifth and sixth members forming A triplet; a seventh convex-plano lens member VII; an eighth plano-concave lens member VIII; said seventh and eighth members forming a doublet; all of said lens members being axially aligned; the parameters of lens radii (R1 - R12), lens thicknesses (T1 T8), axial spaces among lens elements and object plane (S1 S4), refractive indices (ND1 - ND9) and Abbe numbers ( gamma 1 - gamma 9), being determined by the following relationship wherein all radii, thicknesses, and spaces are in millimeters:
 2. An achromatic microscope objective having a magnification of substantially 100X and a numerical aperture of substantially 1.25 for forming an image of an object plane, said image being well corrected for chromatic aberrations, coma, astigmatism, and curvature of image field, said objective comprising: a front plano-convex lens member I; a second concavo-convex lens member II; said front and second members forming a doublet; a third concavo-convex lens member III; a fourth double convex lens member IV; a fifth double concave lens member V; a sixth double convex lens member VI; said fourth, fifth and sixth members forming a triplet; a seventh convex-plano lens member VII; an eighth plano-concave lens member VIII; said seventh and eighth members forming a doublet; all of said lens members being axially aligned; the parameters of lens radii (R1 - R12), lens thicknesses (T1 -T8), axial spaces among lens elements and object plane (S1 -S4), refractive indices (ND1 - ND9) and Abbe numbers ( gamma 1 - gamma 9), being determined by the following relationship wherein all radii, thicknesses, and spaces are in millimeters: 